Encyclopedia - Laser Pointers

What types of laser pointer should you use?
What are the effects of using laser pointers?

Laser pointers are portable, battery-operated, pen-like devices used during presentations to project a beam of laser light. They have replaced traditional pointers used by lecturers, teachers, and others who speak in front of groups. According to a position statement by the American Optometric Association, some laser pointers can deliver light energy into the eye that may be more damaging than staring directly into the sun. Laser pointers usually emit red-colored light.

LASER is an acronym for Light Amplification Stimulated Emission of Radiation, and, since being introduced in 1960, has become commonplace in industry, electronics, entertainment, and medicine. Lasers are different than standard light sources in that they produce a single wavelength of light in a very narrow beam. This means that laser light is highly directional, forming a pencil-like beam that appears as a small spot when shone on a surface even hundreds of yards away. Because the laser light is monochromatic (one color) and projected in a narrow beam, the lens of the eye focuses it better than other light sources. This produces an image on the retina with much greater intensity than possible with standard lighting.

What types of laser pointer should you use?

When used properly, the risk of eye injury from a laser pointer is very low. However, when children or adults misuse pointers, there is the potential for eye injury. The Food and Drug Administration warns that laser pointers are not toys and is alerting parents and school officials about the possibility of eye damage to children. When purchasing a laser pointer, you should be careful to read and understand the label.

According to the American Optometric Association, you should look for a laser pointer that is labeled “Class II” and operates at a wavelength between 630 and 680 nm. Never use a pointer with an output greater than 5mW.

Although laser pointers produce a weak laser light, it is strong enough to produce retinal damage if you look at it for a prolonged period of time. The direct laser beam can cause damage to unprotected eyes. The natural reflex is to close your eyes or blink if exposed to a laser light. However, children may not blink or close their eyes. Because exposure to a laser light can cause discomfort and temporary vision impairment, looking at a laser can be particularly dangerous for people who are engaged in activities such as driving, flying, or operating machinery.

What are the effects of using laser pointers?

The three most common effects of exposure to a laser light are afterimage, flash blindness, and glare. Afterimage is the perception of light, dark, or colored spots after exposure to a bright light. Flash blindness is similar to the effect produced by flashbulbs. Glare is a temporary loss of visibility such as that produced by oncoming headlights. All these effects should be temporary, lasting only a few seconds to a few minutes. If the effects last longer, you should consult an eye doctor.

For your safety, always follow a few basic rules when dealing with laser pointers:

1. When purchasing a laser pointer, choose one that is labeled “Class II,” and read the instructions carefully before using it.
2. Never point the laser toward another person.
3. Never look directly into the laser beam.
4. Never point the laser at a mirror or mirror-like surface.
5. Do not view the beam through a microscope or binoculars.
6. Do not allow children to use laser pointers without adult supervision.